The field of the present invention is mechanisms for joining tubes end to end.
A flange joint assembly previously known is illustrated in FIGS. 1 and 2. A first tube 70 having an end segment 71 is fitted with a steel flange 72 having a central hole 73 so as to fit over the tube 70. The flange 72 is welded to the tube 70 at 74. A second tube 75 is also fitted with a steel flange 76 having a central hole 77 to accommodate the tube 75. The flange 76 is then welded at the tip 78 of the tube 75 and on the other side thereof at 80. A gasket 81 is then positioned against one or the other of the flanges 72 and 76 and the end 71 of the tube 70 is inserted into the end 79 of the tube 75. The outer diameter D.sub.7 of the tube 70 is to provide a clearance fit with the inner diameter D.sub.8 of the tube 75. Fasteners associated with the flanges 72 and 76 then draw the joint together, compressing the gasket 81.
FIGS. 3 and 4 illustrate a second previously known flange joint assembly. The tube 82 having an end portion 83 is associated with a stamped sheet metal flange 84 by inserting the tube 82 in the hole 85 of the flange 84 and welding the two together at 86. A second tube 87 is associated with a second such flange 88 having a central hole 89 to accommodate the tube 87. The flange 88 is welded on both sides at 90 and 91 to the tip 92 of the tube 87. A gasket 81 is again placed in position and the end portion 83 of the tube 82 is positioned in the tube 87. A clearance between the outside diameter D.sub.7 of the tube 82 and the inside diameter D.sub.8 of the tube 87 assist in the positioning of the tubes. Again, fasteners may draw the flanges 84 and 88 together to complete the joint.
With high performance tubing, the foregoing structures and arrangement are satisfactory. However, fabrication is difficult because of the welding required to complete the joint. Strain on the material during welding can lead to defects in the welded area. Welding itself is environmentally unfriendly and subject to defects. Gaskets can also be troublesome under various conditions. Further, such joints can lead to difficulty in disassembly and loose fit resulting from long-term usage.